As shown in FIG. 1, an end effector 16 is the closest part of the industrial robot 15 to the working environment. Usually, gaps are reserved at the exterior structure of the end effector 16 and enables pulverized oil mist or water enter into the inside of the end effector 16 during mechanical machining, so as to cause loss of precision or other damages to the end effector 16. Therefore, a protection apparatus is required for the end effector, which prevents sealability from excessively decreasing, as gear sealing damage may be caused as high pressure liquid and particles may enter into the end effector 16. Another potential problem is grease leakage for the gear sealing because grease might get out directly and pollute other tools or parts during mechanical machining.
For a conventional protection structure, as shown in FIG. 2, a double sealing is used to prevent grease leaking and liquid outside to avoid gear sealing damages. A first oil seal is arranged between a bearing inner ring and a bearing outer ring, and a second oil absorbing member is arranged so as to cover the outside end face of the oil seal. The second oil absorbing member is fitted by using a flexible belt-like holder and a belt-like binding band. The holder is wound around the bearing outer ring, the comb tooth plate parts are pressed to the end face of the second oil absorbing member and the holder is fastened onto the bearing outer ring by using the binding band. However, this structure is too complex and creates concave surface which is difficult for clean.
For this reason, there is a need in the art to develop an improved protection apparatus.